Alan Courtney "Ace" Greenberg (September 3, 1927 – July 25, 2014) was an American businessman who was an executive at The Bear Stearns Companies, Inc., serving as its CEO from 1978 to 1993 and Chairman of the Board from 1985 to 2001.

Greenberg pursued a career on Wall Street after college, accepting a position as a clerk at Bear Stearns for $32.50 per week.

Cayne served as CEO until January 2008 and was succeeded by Alan Schwartz, who oversaw the firm's demise in March 2008.

[5] While serving as chairman of the executive committee of Bear Stearns, Greenberg oversaw the collapse of the company in March 2008.

[6] Fortune reported that Greenberg agreed to join JPMC as vice chairman of Bear's retail business.